Magnetic mixer



sept. 14, 1954 Original Filed Nov. 19. 1949 J- H. HAMMOND, JR

MAGNETIC MIXER 4 Sheets-Sheet 1 :inventor (Umwegv Sept 14, 1954 .1 H. HAMMOND, JR

MAGNETIC MIXER 4 Sheets-Sheet 2 Original Filed Nov. 19. 1949 3 nventor JOHN HAYS HAMMOND, JR.

Gttorncg I fl,

Sept- 14, 1954 .L H. HAMMOND, .1R

MAGNETIC MIXER 4 Sheets-Sheet 3 Original Filed Nov. 19, 1949 :inventor F. i E JOHN HAYS HAMMOND,JR.

Gterneg Sept 14, 1954 .1. H. HAMMOND, .1R 2,689,114

MAGNETIC MIXER Original Filed Nov. 19, 1949 4 Sheets-Sheet 4 g 7g 500 o 0 O O o 78o 67 65 al e5 69 67 '4 25 26 2 f '5 o4 5| 6 7 3| F 32 S l? 2/2 2l 23/ 28 E 83 33 j *#65 A /y 84 f* lhmcntor JOHN HAYS HAMMOND,JR.

Patented Sept. 14, 1954 UNITED 4SCT"VITS OFFICE John Hays Hammond, Jr., LGr'loucester-Ma.ss.

`Original application November 19, 19.49, Serial No. 128,337., now .Patent No. 2,649,288, dated August 18,1953. Divided and .this application August '530, `1952'Serial `No. 307,247

4ing machine which is `provided with lan annular :magnet aiiixed to `the machine and an annular ring of ferrous material.attachedtolthe container, which is Yheld in foperative 2vposition by means of the magnetic attraction between lthe -magnet and 7the-ring.

The inventionalsoprovides -means for normally holding the stirringshaftina :raised position and then lowering it into'an operative vposition when the `machine lstarts `to function.

The, invention further provides imeans for-automatically starting the motor when thefcontainer is placed 4in theoper-ative position.

The invention also provides means for guiding ithe container into the 4proper position whenit-is "placed in the machine.

`'The inventionalso consi-sts in'certainfnew and Aoriginal features of construction land vcombinations .of parts "hereinafter Aset forth 'and claimed.

.Ihe nature of the invention. as to :its 'objects .and advantages, the mode of .its operation 'and `the .manner of its organization, may be better under- .stood by referring v.to .the following description, takenin .connection with the accompanying draw- .ings forming .a .part thereof, in which Fig. 1 isa .side .elevation partly .in section .of .a magnetic .mixer constructed in accordance with the invention, showing the parts in the 'inoperative condition,

Fig. 2 .a bottom plan view .of the mixer taken son line 2 2 vof Rig. l,

Fig. 3 is .a side .elevation .similar to Fig. 1 show-- ing the `mixer provided with a container and .in .operative position,

Fig. 4 .is a .top plan view of thecontainershown in Fig. 3.

Fig. 45 is a :fragmentary side elevation, partly in section, `oi .a modified form of .magnetic mixer, :and

Fig. 6 is a .section taken .on the line .6--6 of liize .reference characters .denote Ilike parts .in the several iiguresof .the drawing.

In -the following ydescription parts vwill beidentied by specific names for convenience, but they 2 are intended to 'be'generic in their-application to similar parts.

AReferring to the form of the .inventionshown in the accompanying drawings and more ,particu- Alarlyto Figs. 1 and "2 a mixing machine II isprovided rwith 'a base IZand an uprightpedestal I3.

Attached to the Vupper end of the pedestal "I13 is a 'motor 14. Secured 'to the lower face of 'the `m'otur I4 is 'a circular plate f5, which is made of 'anysuitablenon-inagnetic material, such as `brass or aluminum. `I focated"between the plate 'I5 and "the 'motor I4 are 'spacers IB.

Surroundingthe circular Aplate I5 and secured thereto 4is a cone shaped guide I"I which `is ,provided .with a large notch I8 on 'the lpart A*facing the pecestal I3. Located in the notch TIB and secured to the pedestal AI 3 isa .cylindrically shaped vvertical V.guide 19.

Mounted on the under surface of the circular iplate lli vis an annular shaped permanent magnet 2l Vwhich is notchedias shown at 22 andZZ. The magneti .is so magnetized that'northand south poles are produced `at the points indicated 'by the letters N andS. 'if so `desired the annular magnet 2l may be divided 'into a plurality .of .short sections each having its own north and south poles.

vPivot-ally mounted iin the pedestal lf3 is ^a contactarm 2.5, Aoneend of which is provided with a curved finger 226 whichrextends .through holes ..23 and 2i! in the .plate VI 5 andmagnet 2l respectively. Normally the arm E5 is heldin the position shown in Fig. 1 by means of a light tension .spring 29.

vIn this position the finger 26 ,projects slightly below the lower surface of the magnet 2l. Mounted on but yinsulated .from the `.arm 25 is .a contactplate 3l which at suitable times `engages `two xed contacts ,'32 and-33 vv'whichare-connected. in an electriccircuit v34, which .is connected to asuitable source of electricityiigand to-.theewindring of thelmotor M, .so that when :the contact ,motor frame .tohold the shaftfl .in position. .The

shaft 31 is provided with two concentric holes 43 and 44 of different diameters each extending approximately half way through the shaft.

Mounted in the shaft 31 and projecting into the hole 44 is a pin 45, which engages a spiral groove 46 provided in a rod 41 which is slidably and rotatably mounted in the hole 44. Wound around the rod 41 is a compression spring 48 the upper end of which is attached to the rod 41 and the lower end to the shaft 31. A cap 49 is mounted on the top of the rod 41 and fits into the hole 43 in the shaft 31. The rod 41 projects downwardly through a hole I in the plate I5 and at its lower end is provided with vanes 52, mixing disc 53 and a propeller 54 which is pitched to exert a downward thrust on the rod 41 due to its rotation in the liquid in the container.

Referring to Figs. 3 and 4, a container 55 is shown which consists of an elongated cone shaped portion 56 to the top of which is attached a ring 51 of ferrous metal of the approximate sizeof the annular magnet 2 I.

Operation of Figs. 1-4

In the operation of the magnetic mixer depicted in Figs. 1 4, the ingredients which it is desired to mix are placed in the container 55, which is then placed in the position shown in Fig. 3. In placing the container in position it will be guided to the proper location by means of the conical guide I1 and the cylindrical guide I9. The container 55 will be held in this position against the force of gravity by means of the magnetic attraction between the annular magnet 2I and the ferrous-metal ring 51 which is in contact therewith.

When the container is placed in position the ring 51 will engage the finger 26 of the contact arm 25, which will be rotated in a clock-wise direction from the position shown in Fig. 1 to that shown in Fig. 3. This motion will cause the contact segment 3I to engage the fixed contacts 32 and 33, thus closing the circuit from the power supply 35 to the motor I4, which will start rotating in a counter-clockwise direction as indicated by the arrow in Fig. 2.

When the motor starts to rotate the parts will be in the position shown in Fig. 1. As the shaft 31 starts to rotate it will tend to carry the rod 41 with it in the same direction. Due, however, to the inertia of the rod 41 and the resistance caused by the varies 52 and discs 53 in the material to be mixed, the rod 41 will tend to hold back and not to rotate as fast as the shaft 31.

This will result in a relative rotation between the shaft 31 and the rod 41 causing the pin 45 to move in the spiral groove 46 with the result that the rod 45 is moved down into the material to be mixed against the force of the spring 48, which at the same time is wound tighter about the rod,41 due to the relative rotation between the shaft 31 and the rod 41. When the pin 45 reaches the top end of the groove 46 the shaft 31 and the rod 41 will be locked together and both will rotate at the same speed.

After the mixing discs 53 have mixed the ingredients sufficiently the container 55 is removed from the machine II manually. When this occurs the pressure of the ring 51 on the finger 26 will be released allowing the contact arm 25 to rotate in a counter-clockwise direction under the action of the spring 29 from the position shown in Fig. 3 to that shown in Fig. 1. This in turn will break the circuit to the motor I4 causing it to stop.

As soon as the shaft 31 has come to a stop the spring 48 will tend to pull the rod 41 up and at the same time will tend to unwind. The combination of these two sections will cause the rod 41 to rotate in a counter-clockwise direction, as seen in Fig. 2, and to move up, thus causing the pin 45 to slide in the spiral groove 46 from the position shown in Fig. 3 to that shown in Fig. 1.

The entire mechanism will now be in the position shown in Fig. 1 where it will remain until the container 55 is again placed in position, at which time the cycle of operations will be repeated.

Of course either the propeller 54 or the pin 45 and spiral groove 46 may be used independently if desired. In either case when the motor I4 stops the spring 48 will return the rod 41 to its initial position.

Referring to the modified form of the invention shown in Figs. 5 and 6, the mixer 6I is of the same general construction as that shown in Figs. l and 2 up to and including the electrical circuit 34. The motor I4 is provided with a shaft 62 having a longitudinal hole 63 therein. End plates 64 are secured to the motor frame to hold the shaft 62 inposition. Slidably mounted in the hole 63 is a rod 65 made of non-magnetic material, which is provided with a longitudinal hole 66 the upper end of which is threaded as at 6l). The rod 65 is also provided with two longitudinal slots 61. A pin 68 is provided which is secured in the shaft 62 and passes thru the slots 61, thus allowing the rod 65 to move up and down in the shaft 62, but preventing it from rotating with respect thereto. A cylindrical plug 66 is mounted in the hole 66 and is held against the pin 68 by means of a compression spring 1I. A core 12 of magnetic material, such as soft iron, is provided with a threaded end 13 which is screwed into the threaded portion 60 of the rod 65 and holds the spring 1I in position.

Mounted on top of the motor I4 is a solenoid 15 having a laminated iron frame 16 and a winding 11, which surrounds the rods 65 and 12. The frame 16 is provided with clearance holes 18 thru which the rods 65 and 12 pass.` A thin sheet metal cover 19 is provided with encases the motor I4 and the solenoid 15.

One side of the winding 11 of the solenoid 15 is connected by a conductor 8| to one side of a resistor 82 the other side of which is connected to a contact 83, which at suitable times engages the contact plate 3l. A switch 64 is connected across the resistor 82, which may be used for short circuiting said resistor, when the solenoid 15 is operated on A. C. The other side of the winding 11 of the solenoid 15 is connected by a conductor 85 to the return conductor of the circuit 34.

Operation of Figs. 5 and 6 i In the operation of the modified form of the invention depicted in Figs. 5 and 6, the container 55 is placed in position in a manner similar to that described in connection with Figs. 1-4. This will cause the arm 25 to be rotated in a clockwise direction causing the contact segment 3| to engage the three contacts 32, 33 and 83.

This action will start the motor I4 rotating and at the same time will energize the solenoid 15 which will cause the iron core 12 to be pulled down into the solenoid 15. As the core 12 is attached to the rod 65 the latter will also be moved down against the action of the spring 1I which is compressed between the core 12 and the plug 69.

It is thus seen that as soon as the motor I4 starts the rod 65 will rotate due to the pin 68 in the slots 61 and at the same time it will be moved down into the ingredients in the container 55 which are thoroughly mixed due to the action of the mixing vanes 53.

This action will continue until the container 55 is removed thus allowing the arm 25 to return to the position shown in Fig. 5 under the action of the spring 29. This will break the circuits to the motor I4 and the solenoid 15, thus causing the motor I4 to stop the rotation of the rod 65.

When the solenoid 'l5 is deenergized the core 12 will no longer be held in the down position, but will be moved upward together with the rod 55 under the action of the spring 1I until the parts have assumed their initial positions as shown in Fig. 5. The mixer will then remain in this condition until it is ready to be used again.

If the mixer is to be used with the D. C. supply, it will be necessary to open the switch 84 thus throwing the resistance 82 in series, with the solenoid winding 11.

Although only a few of the various forms in which this invention may be embodied have been shown herein, it is to be understood that the invention is not limited to any specific construction but may be embodied in various forms without departing from the spirit of the invention.

What is claimed is:

A mixing device comprising a container, a support to hold said container in position for stirring, a motor mounted on said support and having a hollow vertical shaft, a stirring rod mounted in said shaft to be driven thereby and sliding axially between retracted and stirring positions, a` key and thread connection between said stirring rod and said shaft adapted to feed said rod downwardly in response to rotation of said shaft in driving direction with respect to said rod, and a spring connecting said shaft and said rod to be stressed by said relative rotation and to cause reverse relative rotation of said rod and shaft for retracting said rod when the drag on said rod is released.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 1,431,715 Wolters Oct. 10, 1922 1,764,906 Steiner June 17, 1930 

